Muon flux

The pion decay kinematics implies that the created muon spectrum is within 0.57 <p_µ / p_π < 1.0, where the peak is at about 85 % of the pion momentum. Some results from a simulation for H8 using HALO are shown here. These are valid for H2 and H8, as these two beam lines are very similar. All profiles are monitored at the position of the ATLAS trigger located 40 meter downstream of the last bend of the VLE setup. In H2, H2A/CMS HCAL is located 50 meter downstream of the last VLE bend.

Below a pion beam of 180 GeV/c is transported in H8 with full acceptance. The full halo beam if shown in the first row, where the second row shows the muon momentum within a trigger of 100x100 mm². The right lower plot indicates the relative rate of muons and pions within two different areas.

The impact of the bends in the VLE setup is shown below. In the simulation a 80 GeV/c secondary beam was assumed, were the VLE setup is running not at all and at 5 GeV/c. In latter case the muon beam is displaced by almost a meter. Depending on the polarity of the secondary beam and the one of the VLE beam, the displacement can be either towards Jura or Saleve (think hard!). To install a muon veto trigger in the straight beam path just upstream of the last bend in the VLE setup is within the responsibility of the user.